She insisted that the object she hit last summer was not a person, telling the court, "I just never saw him. I didn't see him. It just couldn't have been me."
When asked to describe what the feeling of the impact was like she said: "I've never been in an accident so I wasn't quite sure if I'd hit a pothole or one of those construction signs."
"I remember being jolted by the front," Senser testified. "Not exactly sure what had happened. I assumed I had hit something."
Senser, who is married to Joe Senser, a former Minnesota Vikings tight end, is being tried on three felony counts of criminal vehicular homicide in the death of 38-year-old Anousone Phanthavong. She is accused of failing to stop, failing to contact police as soon as possible and causing Phanthavong's death by driving in a "grossly negligent" manner, according to the Pioneer Press newspaper.
Phanthavong, a restaurant cook, was fatally struck by a sport utility vehicle as he refueled his stalled car on an Interstate 94 ramp in Minneapolis on the night of August 24. Last September an attorney for the Sensers acknowledged that Amy Senser, 45, had been driving the vehicle that hit Phanthavong.
Senser in her testimony on Monday inside Hennepin County District Court in Minnesota gave tearful testimony about that night.
She told jurors that she'd had part of a glass of wine before meeting her daughter and her daughter's friends at a Katy Perry concert in St. Paul, but left early because she wasn't feeling well, intending for her husband to pick up the girls. On her way home, she changed her mind and turned back, but she got lost and called her husband to get the girls.
Senser testified she felt an impact after she exited a freeway in her Mercedes SUV on Aug. 23 in Minneapolis, but said she thought she'd hit a construction barrel or pothole.
Senser said it wasn't until the next morning, when Joe Senser called her outside to look at her car, that she realized how much damage had occurred. The couple then saw a news report on Phanthavong's death.
Prosecutor Deborah Russell pressed Senser on deleting numerous text messages between herself, her daughter, her husband and other people the night of the crash. Senser said she exchanges a lot of texts — 1,400 per month based on a phone bill introduced in court — and frequently deletes them. She said she wasn't trying to conceal evidence.
The Sensers contacted an attorney and authorities the day after the accident, but it was more than a week before Amy Senser acknowledged to police she was the driver.
Senser's husband, teenage daughters, stepdaughter, and several experts have been among the 24 people called to the stand since the trial started April 23.
Experts have testified that it would have been difficult to see Phanthavong or the flashing lights on his car because of the construction, disconnected streetlight and the curving roadway, according to the Minneapolis Star Tribune.
In testimony last week, Senser's stepdaughter, 28-year-old Brittani Senser, said on the stand that she forced her stepmother to admit her involvement in the accident.
Brittani Senser testified that she was angry after media reports linked her to the accident, adding that she was concerned because her fiancé knew Phanthavong's brother, and people began to ask her if she was involved in the victim's death, the Star-Tribune also reported.
"I wanted my dad to stand up for me and say I didn't do it," she told jurors, adding, "for people to think I killed someone made me angry."
Amy Senser's defense lawyers countered that Brittani Senser was actually angry that the hit-and-run had caused damage to her career -- saying that the 28-year-old was more upset about losing a charity singing gig than Phanthavong's death.
The case could be turned over to the jury as early as today.
Each of the counts Senser faces carries a 10-year prison sentence.
The Associated Press contributed to this report.