The exact number of exonerated American prisoners is unknown. But data gathered by university law schools indicates it's more than 2,000. Fascinating details surrounding some of these exonerations set them apart from the rest. Here are five recent exonerations that made headlines.

1. Michael Morton

The subject of a CNN film, Michael Morton wasn't home when his wife, Christine, was beaten to death in front of their 3-year-old son at their Austin, Texas-area home in 1986. But a prosecutor said the evidence suggested otherwise. The problem was, the jury was prevented from hearing all the evidence in the case.

Wrongly convicted of murder and sentenced to life in prison, a team of loyal supporters and DNA evidence helped Morton win his freedom in 2011. Last month, Morton's former prosecutor pleaded no contest to a court order to show cause regarding evidence that was not used in the trial.

Read more about Michael Morton's story

2. Brian Banks and the incredible twist

At age 17, fearing a potentially long sentence, college football hopeful Brian Banks followed the advice of his attorney and pleaded no contest to assaulting a Long Beach, California, high school classmate in 2002.

Banks maintained his innocence throughout nearly six years of imprisonment, subsequent probation and registration as a sex offender.

But in 2011, the case took an incredible twist when the alleged victim sent Banks a Facebook friend request.

According to the California Innocence Project, the woman later admitted that Banks had not kidnapped or raped her during a consensual encounter at Long Beach Polytechnic High School, where Banks was a middle linebacker with a scholarship offer from the University of Southern California.

Answer the following questions:
1. How many been exonerated in US?
2. Who provided the info?
3. Whose wife was killed?
4. What was her name?
5. Was he at home at that time?
6. Was there any one else?
7. Who?
8. How old was he?
9. When this happened?
10. In which state?
11. Who got punished for the crime?
12. What was the sentence?
13. Then what happened?
14. When?
15. How?
16. How old was Banks?
17. What was he accused of?
18. What did he plead?
19. Then what happened?
20. When?
1. more than 2,000
2. university law schools
3. Michael Morton
4. Christine
5. no
6. 3-year-old son
7. his son
8. 3-year
9. 1986
10. Texas
11. Morton
12. life in prison
13. won his freedom
14. 2011
15. DNA evidence
16. 17
17. assaulting
18. no contest
19. victim retracted
20. in 2011