My boyfriend was charged with aggravated assault in Texas in 2002. He served a year in prison then got 10 years probation.

My boyfriend was charged with aggravated assault in Texas in 2002. He served a year in prison then got 10 years probation. After serving over 7 years of the probation he was charged with a felony DWI. Being afraid he fled Texas and went to ND to work. After a time he relocated to Iowa for work. While in Iowa he met me and we got engaged. He has had no trouble with the law since leaving Texas. Yesterday the U.S. Marshalls came to our home with guns drawn and took him into custody. He is currently sitting in a Spencer county jail. He met with a judge this morning and was asked to sign a waiver of extradition. He has not done this because he has no court-appointed attorney since he has not committed any crimes in the state of Iowa. Should he sign this waiver of extradition? What kind of sentence is he possibly facing? If sentenced to prison time or probation would it be possible to serve it in Iowa? The warrant was for motion to provoke probation and felony DWI. Please help.